1. Technical Field
The present invention relates to a medium processing device that records on a recording medium, and a control method for the medium processing device.
2. Related Art
Medium processing devices that convey a medium along a medium conveyance path from an entrance to an exit and record information on the medium are generally known. For example, a check is inserted in a device that prints information on the check and then expels it. These devices have a medium insertion detector that detects insertion of a recording medium from the entrance to a medium conveyance path, a medium discharge detector that detects discharge of the recording medium from the exit of the medium conveyance path, and a recording means that records on the recording medium, are known from the literature. Medium processing devices of this type commonly use photosensors as the medium detectors for reasons including assembly precision. Photosensors can detect if a recording medium is present or not by emitting light from a light-emitting device, and then detecting the reflection when the recording medium is present and the reflection when the recording medium is not present by means of a photodetector. See, for example, Japanese Unexamined Patent Appl. Pub. JP-A-2002-68529.
Depending upon where the medium processing device is used, however, ambient light from the sun, for example, may enter from the paper entrance or paper exit and be picked up by one of the photodetectors in this type of medium processing device, and the medium processing device may incorrectly detect that recording medium is present when the recording medium is not present.
Detection errors caused by ambient light can be avoided in this situation by repeating the detection operation of the medium detectors several times, and recognizing the detection result (whether the recording medium is present or not) when the same detection result is received several times in succession. However, this configuration requires more time to validate the detection result of the medium detector, and if the user removes the recording medium from the conveyance path during this time, detecting that the recording medium was removed may not be possible.